As is known, there are a number of load sensing devices useful for measuring forces exerted on a body. For example, U.S. Pat. No. 4,738,325, issued to Bullivant, et al., discloses a Hall-effect weight transducer. The transducer senses changes in the magnetic field generated by a pair of magnets affixed to a housing. The field change is due to the relative movement of the upper and lower inner surfaces of the housing from the application of a weight to the housing.
U.S. Pat. No. 4,745,811, issued to Gray, discloses a pressure monitoring apparatus. The apparatus utilizes a pressure gauge having Bourdon tube with a pair of magnets affixed thereto. The tube is responsive to external pressure and a hall effect detector mounted in close proximity to the magnets generates a signal proportional to the movement of the magnets.
U.S. Pat. No. 4,866,854, issued to Seltzer, discloses a multi-axis displacement sensor for sensing the movement of two relatively movable parts. The sensor includes at least two magnetic poles mounted on one of the movable parts and two hall effect devices mounted on the other part. A displacement of the parts causes relative movement between the Hall-effect devices and the magnetic poles.
U.S. Pat. No. 3,974,491, issued to Sipe, discloses a device for signaling a patient when a predetermined load is placed on the patient's foot. The signaling device utilizes a resilient foot pad having a liquid filled tube and is controlled by a pressure responsive means in communication with the tube.
U.S. Pat. No. 4,647,918, issued to Goforth, discloses a notification system for monitoring critical pressure points on the feet of persons having diminished sensation of the feet. The systems utilizes a plurality of pressure transducers electrically connected to a microprocessor. An alarm indicates when a predetermined threshold of pressure is exceeded.
U.S. Pat. No. 4,745,930, issued to Confer, discloses a force sensing insole for use with an electro-goniometer for analyzing the gait of a patient. Normally open contact switches positioned in the open chambers of the body member are brought into contact with each other upon a compressive force applied to the insole.
U.S. Pat. No. 4,813,436 discloses a motion analysis system having pressure responsive shoes or insoles worn by the subject. The insoles utilize pressure transducers and provide signals which are processed, whereby a display indicates the pressure applied to the subject's foot while moving.